/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/ViewModels/NiagaraEmitterViewModel.h
Gets editor specific data which is stored per emitter. If this data hasn't been created then it will be created.
[UNiagaraEmitterEditorData](API\Plugins\NiagaraEditor\UNiagaraEmitterEditorData) & GetEditorData()